Embodiments of the invention relate generally to electrical shields and, more particularly, to a method and apparatus for forming a conformal shield for an electrical system.
Technological advancements in the area of electronic devices have experienced vast growth in recent years. For example, while cellular phones are becoming smaller and lighter, their features and capabilities are simultaneously expanding. This has caused an increase in the complexity and operation of the electrical components found in such devices and a decrease in the amount of space available for such components. In such electrical devices, many electronic components radiate electromagnetic radiation, which may cause interference with other electrical devices. Radio frequency and electromagnetic interference (i.e., RFI and EMI) may detrimentally affect the performance and operation of other electrical devices. As a result, shields have been used to prevent such components from causing such interference.
The most common RFI/EMI shields are box-type shields comprised of a single piece of folded or stamped metal (i.e., metal cans, metal foil claddings, etc.) contoured to fit over a PC board. Space must be allocated on the circuit board to accommodate these box-type shields, which reduces the space available for other components. That is, conventional box-type shields are bulky and take up a great deal of space and volume, a majority of which is an unused air gap between the circuit board and the shield. This can add to the overall thickness of an electronic device (e.g., a cellular phone). Additionally, a product may have many components requiring RFI/EMI shielding from other components within the product as well as from external sources. Depending on the number of the shields needed, significant weight and cost may be added to the product.
Another drawback of typical box-type shields is that they are soldered onto the circuit board. Such soldering of the box-type shield to the circuit board makes it difficult to re-test or rework the circuit board, as it is extremely time consuming and difficult to unsolder and remove the RFI/EMI shield originally in place. Furthermore, the facilitation of a shielding redesign made late in the product design cycle, which may be necessary after product testing, is extremely difficult with space consuming box-type shields that are soldered onto the circuit board.
Therefore, it would be desirable to design a low profile, low weight, high performance RFI/EMI shield. It is further desired that such a shield allow for efficient re-testing and reworking of a circuit board or other electrical system.